Activision had a lot of success of the Wii; Skylanders, Goldeneye 007, COD3/W@W/MW/BO...
First, that's why i said partially. Activision sold from ok to good on Wii, their Wii U games mostly flopped though and they haven't been all to successful on handhelds for quite some time.
At the same time some games just aren't that easy to port. I really think Bethesda did a good job with Skyrim and Doom. Other titles might be harder to port though. And yes, those ports take time.
At the same time we can be pretty sure that most of the big publishers didn't put much trust in Switch, if any. We might see more multiplat games within the next months. Some of them will be older titles. And at least some, more likely many games will never be ported to Switch.
I'm not sure if that's to bad though. With good japanese support, indie games, maybe some western exclusives and yes, even smartphone ports we might actually see a Switch library that is rich yet different from what 'everyone else' does.